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/*====================================================================*
- Copyright (C) 2001 Leptonica. All rights reserved.
- This software is distributed in the hope that it will be
- useful, but with NO WARRANTY OF ANY KIND.
- No author or distributor accepts responsibility to anyone for the
- consequences of using this software, or for whether it serves any
- particular purpose or works at all, unless he or she says so in
- writing. Everyone is granted permission to copy, modify and
- redistribute this source code, for commercial or non-commercial
- purposes, with the following restrictions: (1) the origin of this
- source code must not be misrepresented; (2) modified versions must
- be plainly marked as such; and (3) this notice may not be removed
- or altered from any source or modified source distribution.
*====================================================================*/
/*
* skewtest.c
*
* Tests various skew finding methods, optionally deskewing
* the input (binary) image. The best version does a linear
* sweep followed by a binary (angle-splitting) search.
* The basic method is to find the vertical shear angle such
* that the differential variance of ON pixels between each
* line and it's neighbor, when summed over all lines, is
* maximized.
*/
#include <stdio.h>
#include <stdlib.h>
#include "allheaders.h"
/* deskew */
#define DESKEW_REDUCTION 2 /* 1, 2 or 4 */
/* sweep only */
#define SWEEP_RANGE 5. /* degrees */
#define SWEEP_DELTA 0.2 /* degrees */
#define SWEEP_REDUCTION 2 /* 1, 2, 4 or 8 */
/* sweep and search */
#define SWEEP_RANGE2 5. /* degrees */
#define SWEEP_DELTA2 1. /* degrees */
#define SWEEP_REDUCTION2 2 /* 1, 2, 4 or 8 */
#define SEARCH_REDUCTION 2 /* 1, 2, 4 or 8 */
#define SEARCH_MIN_DELTA 0.01 /* degrees */
main(int argc,
char **argv)
{
char *filein, *fileout;
l_float32 deg2rad;
l_float32 angle, conf;
PIX *pixs, *pixd;
static char mainName[] = "skewtest";
if (argc != 3)
exit(ERROR_INT(" Syntax: skewtest filein fileout", mainName, 1));
filein = argv[1];
fileout = argv[2];
deg2rad = 3.1415926535 / 180.;
if ((pixs = pixRead(filein)) == NULL)
exit(ERROR_INT("pixs not made", mainName, 1));
#if 1
pixd = pixDeskew(pixs, DESKEW_REDUCTION);
pixWrite(fileout, pixd, IFF_PNG);
pixDestroy(&pixd);
#endif
#if 0
if (pixFindSkew(pixs, &angle, &conf)) {
L_WARNING("skew angle not valid", mainName);
exit(1);
}
#endif
#if 0
if (pixFindSkewSweep(pixs, &angle, SWEEP_REDUCTION,
SWEEP_RANGE, SWEEP_DELTA)) {
L_WARNING("skew angle not valid", mainName);
exit(1);
}
#endif
#if 0
if (pixFindSkewSweepAndSearch(pixs, &angle, &conf, SWEEP_REDUCTION2,
SEARCH_REDUCTION, SWEEP_RANGE2, SWEEP_DELTA2,
SEARCH_MIN_DELTA)) {
L_WARNING("skew angle not valid", mainName);
exit(1);
}
#endif
pixDestroy(&pixs);
exit(0);
}
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